Once again scientists have released hysteria-inducing information about pregnancy, then urged people not to freak out. A study found that a high exposure to electromagnetic fields, which are emitted by microwaves and other household appliances, during pregnancy more than triples the chance that a child will develop asthma. The study could be a significant breakthrough, but experts say pregnant women shouldn't be relocating to Amish communities just yet.

Timereports that for a study conducted by Dr. De-Kun Li, a reproductive and perinatal epidemiologist at Kaiser Permanente, pregnant women wore monitors that recorded their exposure to low-frequency electromagnetic fields. These are emitted by nearly anything that uses electricity, including microwaves, vacuum cleaners, hair dryers, refrigerators, stoves, cars, and power lines. The study didn't track exposure to higher-frequency magnetic fields that are emitted by cell phones and wireless networks because they may be nearly impossible to avoid. (Apparently steering clear of all household electric devices is considered doable.)

Thirteen year after the women gave birth, Li's team recorded the number of asthma cases among the children. They found about 13% of the children with the lowest EMF exposure in utero suffered from the condition, compared to 33% of children with high EMF exposure. The rate of asthma in the low EMF group was on par with the national average, while the high EMF group had a 350% increased risk of developing the condition.

Li says pregnant women can limit EMF exposure by making minor changes like not standing in front of the microwave while it heats food, holding the hair dryer away from their stomach, or switching to battery-powered devices. However, Dr. David Savitz, a professor of community health and obstetrics and gynecology at Brown University, tells WebMD that may be an overreaction.

Savitz, who wasn't involved in the research, says that the huge increase in asthma cases among women with high EMF exposure is, "A striking figure ... That magnitude of association we don't see very often. If it was correct, and that's a big ‘if,' that would be really startling." Savitz and other experts say the dangers of EMF exposure are still questionable, but he notes:

"There are a lot of important topics that started out looking pretty flaky and pretty unlikely. There was a time when it made no sense that smoking could be bad for you."

So much like the conflicting biyearly reports on whether or not cell phones are giving us all cancer, it's just too soon to say for sure that EMF exposure poses a significant risk to the fetus. In the meantime, pregnant women should feel free to either obsessively purge the house of any electronic equipment or totally ignore the research and hope for the best.